Portable back massager



FIG. 1 represents both top and bottom plan view of a portable back massager showing my design as they are a mirror image of each other;

FIG. 2 represents both right and left side elevational views as they are a mirror image of each other.

FIG. 3 represents the front elevational view; and,

FIG. 4 represents the rear elevational view. 

CLAIM The ornamental design for a portable back massager, as shown and described. 